Hot swap refers to the ability to replace or add components in a computer or electronic device without shutting down the system. This feature is particularly useful in servers and high-availability systems, where downtime can lead to significant disruptions. Components like hard drives, power supplies, and even some circuit boards can be swapped out while the system is still running. This technology relies on specific hardware and software support to ensure that the system can recognize and integrate the new component seamlessly. Hot swapping enhances system reliability and maintenance efficiency, allowing for upgrades and repairs without interrupting ongoing operations.